Double-Face Activity of Resveratrol in Voluntary Runners: Assessment of DNA Damage by Comet Assay

Abstract

Voluntary runners are subjected to a massive increase in reactive oxygen/nitrogen species production, which can promote different oxidative stress-related diseases such as premature aging, neurodegenerative disorders, and cancer. The aims of this work were to evaluate the following in peripheral blood cells of voluntary runners: (i) DNA status; (ii) susceptibility to the in vitro insult induced by hydrogen peroxide (H(2)O(2)) as a breaking agent; (iii) capabilities of 3,5,4'-trihydroxystilbene (RESV) in counteracting DNA damage. Twenty-five male voluntary runners were compared with 20 sedentary men, as age-matched controls, and DNA status was evaluated with different versions of comet assay: alkaline, neutral, and Fpg enzyme-modified version to measure 8-OH-deoxyguanosine (8-oxo-dG) levels. The H(2)O(2) and/or RESV treatments were performed directly on agarose-embedded cells (atypical comet assay). The results evidenced DNA damage and levels of 8-oxo-dG higher in runners than in sedentary control subjects. The runners' DNA was more prone to the in vitro-induced oxidative insult (200 μM H(2)O(2)) than that of the control group. Resveratrol (100 μM), depending on the individual basal DNA status, was able to switch from antioxidant to pro-oxidant. Our results, on the one hand, validated the proposed in vitro experimental protocol in order to measure individual DNA status. On the other hand, our data point out the importance of monitoring the athletes' redox status before subjecting them to dietary supplementation treatment.

Exercise and oxidative stress: Potential effects of antioxidant dietary strategies in sports

“…Resveratrol may be cited as example for the change between antioxidant/prooxidant effects, because at 100 µM was able to switch from antioxidant to pro-oxidant, exacerbating in vitro DNA damage in same samples from runners, depending on the individual basal oxidative stress status [51]. Moreover, other parameter which be considered in case of analysis of data pertaining to antioxidant supplementation, which account for the great heterogeneity of data, include type of antioxidant (alone or in combination) and dose and duration time of the treatment.…”

Effects of physical activity on systemic oxidative/DNA status in breast cancer survivors

“…The alkaline and neutral Comet assay protocol was performed as previously described by Tomasello et al (18). Triplicate samples (each 40 µl) mixed with 0.5% low-melting point agarose were spread on FLARE™ Slides (Trevigen, Inc., Gaithersburg, MD, USA), immersed in cold lysis solution for 1 h, and electrophoresed for 20 min in alkaline (pH >13; 0.7 �/cm) or neutral buffer (pH 8; 0.5 �/cm).…”

Protective effects of resveratrol against X-ray irradiation by regulating antioxidant defense system

“…Resveratrol pretreatment has found to reduce oxidative stress induced by H 2 O 2 in RPE cells, by increasing the activities of SOD, GPx and CAT and also enhancing the levels of reduced glutathione (GSH) as well as direct scavenging the ROS in RPE cells (Sheu et al, 2010;Pintea et al, 2011). Several lines of evidences indicate that resveratrol has a potential to switch from antioxidant to pro-oxidant behavior (Tomasello et al, 2012;Dobrzynska, 2013). This polyphenol has antioxidant activity at lower doses and acts as pro-oxidant at higher doses (Murias et al, 2005).…”